Shim



July 9, 1940 D. M. PAx'roN l 2,207,332

. SHIM l Filed June 15, 1939 /N VEN To@ @e we Y /"/'r. PAX TON Y of ArroQ/ve yf i Patented vJuly 9, 1940 UNITED N sr AsHnvi Dewey M. Paxton, Los Angeles, Calif., assigner, by mesne assignments, to Curtis Anti-Vapor Pumps, Inc., VLos Angeles, Calif., a corporation of California Application June 1s, 1939, serial No. 228,816 7 claims. (Gemss) This invention relates tomachinery generally, and more particularly to means by which wear orinaccurate mountings of working parts can be compensated for, in orderV to restore such parts to their original or to increased dimensions or predetermined operating relationships, and thus prolong the useful life of the mechanism.

An object o-f this invention is to provide a shim particularly adapted, although not necessarily for use with a liquid fuel pump of the type installed on internal combustion engines, the shim being applicable to a cam operated actuating member of the pump in a manner to eifectively compensate for Wear on the actuating member and/or cam, as well as dimensional inaccuracies 0f the pump and its mounting on the engine, which individually or collectively result in such a decrease in pumping capacity of the pump that the latter is unable to supply the amount of fue-l necessary for operation of the engine.

Another object of the invention is to .provide a shim which can be applied to the actuating member of the fuel pump Without altering the construction of the member; which can be applied without the use of tools, and requires no extraneous fastening means; and which is'co-actable with a structural feature off the actuating member in a manner to be supported thereby in operative relation to the cam, as well as being self-adjusting in its `applied position so as to accommodate itself to varying relationships between the actuating member andcam.

With these and other objects in View, the invention resides in the combinations, arrangements and functional relationships of elements as set forth in the following specication and pointed out in the appended claims.

In the accompanying drawing,

Figure 1 is a View in side elevation, `and partly in section, of a fuel pump installation of an automobile engine, and illustrating a shim embodying this invention applied to the cam operated actuating member of the pump;

Figure 2 is a sectional view taken on the line 2-2 of Figure 1; Figure 3 is a perspective view of the shim;

Figure 4 is a fragmentary view of a portion of Figure 1, showing a filler member used with the shim;

Figure 5 is a perspective View of the filler member.

It is a common occurrence in certain types and mountings of liquid fuel pumps as at present installed on automobile engines, for such pumps to be deficient v.in pumping capacity so as tobe incapable of delivering the requisite amount'of fuel to the carbureter of the engine for operation of the latter under any and all conditions.

A` type of fuel pump in which this deiiciency has been found to exist in practice is illustrated inv Figure l vand is similar to that disclosed in U. S. Patent No. 1,905,207, issuedto M. A. Babitch et al. This pump generally includes fa body'lll co-acting with a head II and a flexible diaphragm I2 clamped therebetween by screws I3, toprovide a pumping chamber I4.

` A stem l5 is secured centrally to the diaphragm I2 and is actuated by a sectional lever I6 against the urgingaction of springs I'l and I8. A motion receiving section of the lever I6 projects through an opening I9 in the body l0 and through an vThe motio-n receiving section of the lever I6 'fis a laminated structure as shown in Figure 2, the laminations of which are secured together by headed pins, rivets or other fastening means as indicated at 2l and 28 in Figures 1 and 2.

The shim S embodying this invention is constructed of sheet metal such as spring brass or` other suitable bearing material bent into substantially U-form to provide a bearing or wear receiving portion 3U and two spaced 'springat-v taching portions 3l having alined slots 32 therethrough, all as clearly shown in Figure 3.

The spacing between the attaching portions 3 I when in parallelism, is substantially equal to the thickness of the motion receiving section of the lever I6 at its point of engagement by the cam 22, and the slots 32 are of suicient Width to receive the heads of the rivet 28.

In the use of the invention on the lever I6 of a pump in which the mounting of the latter on the crankcase 2l is inaccurate to the extent of improperly presenting the lever to the cam 22 so that the latter cannot impart the predetermined stroke to the lever, or in which the lever is inaccurately related to the pump body, or the lever and/or the cam have become worn, all with a lsimilar result, `a shim S of a thickness to com- With the shim thus applied and the pump again attached to the crankcase as shown in Figure l, the portion 30 of the shim will be interposed between the lever and the cam so that the latter can impart the increased movement to the lever necessary to restore the rated pumping capacity to the pump.

In order to obviate the need for stocking shims of various thicknesses to compensate for greater or lesser clearances to be taken up between the lever I6 and cam 22 in different pump installations, an ineXpensive-ller member F (Figures 4 and 5) can be provided for use in conjunction with the shim S, which latter can be of the minimum gage found necessary in practice to compensate for lost motion between the lever and cam.

The filler member can be provided in different gages, such as .025, .050, and .075 of an inch, and be constructed of brass, whereas the shim S can be constructed of spring tempered steel so that its wear receiving portion 30 affords maximum resistance to wear by the cam. The liller member is merely a rectangular stamping of a length and width enabling it to t freely between the attaching portion 3l and against the confronting inside face of .the portion 30 as shown in Figure 4. The filler member is provided `with lugs 33 adapted to enter the slots 32 of the shim, so that in the installed position of the latter, the iiller member will be positively confined against displacement from between the shim and the lever i6, and will co-act with the shim to add the necessary thickness thereto toy compensate for whatever lost motion may exist between the lever and the cam.

What is claimed is:

l. A shim for a motion receiving member of a mechanism, comprising a wear receiving portion and spaced resilient attaching portions adapted to straddle the motion receiving member; the attaching portions having openings adapted to receive projections on the motion receiving member upon springing of said attaching portions over the projections, whereby to secure the shim to the member.

2. A shim comprising a U-shaped body dening a wear receiving portion; spaced attaching portions projecting from the wear receiving portion, and having openings adapted to receive projections on a member to detachably secure the shim thereto with said wear receiving portion thereof disposed for engagement by a second member. f

3. In a fuel pump having an actuating member including a lever arm provided with oppositely disposed projections; a shim having a wear receiving portion and spaced attaching portions adapted to straddle the lever arm; and means adapted for co-action with'the projections of the lever arm to detachably secure the shim thereto with said wear receiving portion disposed for wearing engagement with a second member.

4. In a fuel pump having an actuating member including a lever arm provided with oppositely disposed projections; a shim having a wear receiving portion and spring attaching portions spaced suiciently to receive the lever arm therebetween; the attaching portions having slots adapted to receive the projections of the lever arm when the attaching portions are sprung over the projections, whereby to detachably secure the shim on the lever arm.

5. A shim comprising a U-shaped body clening a wear receiving portion; spaced attaching portions projecting from the `wear receiving portion, and having openings adapted to receive projections on a member to detachably secure the shim thereto with said wear receiving portion thereof disposed for engagement by a second member; a filler member;` and lugs on the filler member adapted to enter said openings to confine the ller member against displacement from between the wear receiving portion and the first said member.

6. A shim for a motion receiving member of a mechanism comprising: a wear receiving portion and spaced resilient attaching portions adapted to receive the motion receiving member therebetween; and means on the shim adapted for coaction with projections on the member to secure the shim thereto when said portions of the shim DEWEY M. PAXTON. 

